It is often desirable to monitor signals being transmitted between a LCC (Leadless Chip Carrier) and the circuit of a printed circuit board to which the LCC is connected. The LCC is typically held in a LCC socket which plugs into the circuit board. A simple low-cost LCC socket does not have any exterior terminals for connection to test equipment. It is possible to use a special LCC socket with such externally-accessible terminals, but if it is desired to make a test on an ordinary circuit then it would be necessary to remove the socket already in place and replace it with a special purpose socket. An adapter which permitted the testing of signals passing between an LCC and an ordinary low-cost socket which normally holds the LCC, would aid in the testing of circuits. Such an adapter would be even more useful if it permitted separate testing of the circuit connected to the socket in the absence of the LCC, and separately permitted testing of the LCC when it was not connected to the circuit to which the socket is connected.